Audio interface



FIG. 1 is a rear perspective view of an ornamental design for an audio interface;

FIG. 2 is a front perspective view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a left side view thereof;

FIG. 7 is a rear elevation view thereof; and,

FIG. 8 is a front elevation view thereof. 

CLAIM The ornamental design for an audio interface, as shown and described. 